KR101650592B1 - Electroactive optical device, assembly thereof, and method for manufacturing electroactive optical device - Google Patents

Abstract

The present invention relates to an electroactive optical device comprising an optical element (1) and an electroactive element (2), in particular to an electroactive lens. The optical element 1 is an elastic solid such as a gel or a polymer. The electroactive device 2 includes a plurality of conformable electrodes 3a to 3e stacked on top of each other with an electroactive material 5 interposed therebetween. The electroactive device 2 is surrounded by rigid walls 4a and 4b which provide two common contacts for the electrodes 3a to 3e. If no voltage is applied, the optical element 1 is placed in a mechanically relaxed state to reduce the unintended aging action. When a voltage is applied to the electrodes 3a to 3e, the optical element 2 is deformed.

Description

TECHNICAL FIELD [0001] The present invention relates to an electro-active optical device, an assembly of an electro-active optical device, and a method of manufacturing an electro-active optical device,

The present invention relates to an electro-active optical device, in particular an electro-active lens, and a method of manufacturing such an apparatus.

An electro-active optical device is an optical device whose shape can be changed using an electro-active effect. In particular, an electro-active optical lens is a lens whose focal distance can be changed using an electro-active effect.

The term electroactive effect means an electric field induced deformation in solid or liquid phase. The deformation may be due to the Coulomb force between the electrodes in the electric field and / or by the rearrangement of the electric ions and / or poles, especially dipoles. Examples of electroactive materials include dielectric elastomers, electrostrictive relaxor ferroelectric polymers, piezoelectric polymers (PVDF), (thermally) liquid crystal elastomers, ionic polymer metals Composite materials, and mechanochemical polymers / gels.

Various designs of electro-active lenses are known.

For example, International Publication No. WO 2008/044937 discloses an apparatus in which a circular-shaped piezoelectric crystal provides a shift of the focal length of the lens assembly by bending a thin glass cover. However, devices based on piezoelectric crystals are relatively expensive to manufacture.

International Publication No. WO 2005/085930 relates to an adaptive optical element that can be constructed, for example, as a biconvex lens. The lens consists of a polymer actuator comprising an electroactive polymer layer and a layer electrode. Applying a voltage of about 10 kV or more causes deformation of the polymer layer, which results in direct deformation of the lens. It is not suitable for many applications because it requires high voltage to control these devices.

In addition, these types of prior art devices exhibit aging phenomena that degrade the properties of these devices over time.

Finally, various devices using liquid filled lenses are known. These devices have several disadvantages. In particular, these devices are likely to be distorted by external forces such as acceleration, gravity effects, or vibration.

It is therefore an overall object of the present invention to provide a device of the type that is reliable and can overcome at least some of the disadvantages mentioned.

This object is achieved by the electroactive device of claim 1. Thus, the apparatus comprises an elastic optical element and an electro-active element arranged laterally adjacent to the elastic optical element. The electroactive device comprises at least one electrode pair having an elastomeric electroactive material, advantageously a dielectric elastomer, and the elastomeric electroactive material is arranged between the electrodes of the electrode pair. When a voltage is applied across an electrode pair, the axial distance between the electrodes of the electrode pair changes, i.e. increases or decreases, whereby the volume of the first region of the optical element adjacent to the electrode pair changes elastically (i.e., Lt; / RTI > Again, this induces a radial displacement of the material in the optical element between the first and second regions. One of the regions elastically expands in the axial direction and the other region elastically contracts. In a state in which no voltage is applied across the electrode pairs, the optical element is mechanically relaxed.

By changing the axial extension of the two regions to radially displace the material of the optical element, a large change in the surface curvature of the optical element can be achieved.

This design utilizes the advantages of an electroactive actuator, such as its potential easy manufacturing process, large deformation and low operating voltage, while at the same time the device is in an elastically relaxed state with no voltage applied, Thereby providing a solution with a long operating life since it is less fatigue than a device formed by a pre-strained solid and placed under continuous deformation.

Preferably, application of a voltage will reduce the spacing between the electrodes, which again will reduce the volume of the first region of the optical element. In addition, the compressed electroactive material between the electrodes may apply a lateral pressure on the optical element. The combination of these two effects makes the optical element in a large deformed state.

In most cases, this effect will lead to an increase in the thickness of the optical element upon voltage application to the electrode pair.

Preferably, the electroactive device comprises a plurality of electrode pairs stacked one on top of the other, with a gap between the electrode pairs. The gap is preferably filled with an electroactive material. Such a design makes it possible to achieve a large volume displacement of the material in the optical element using a small driving voltage.

In another aspect of the present invention, it is an object to provide an effective manufacturing method for such an apparatus. This object is achieved by the second independent claim. According to this,

a) providing a plurality of first electrodes;

b) applying a layer of electroactive material on said first electrode,

c) applying a plurality of second electrodes over the first electrode, wherein each second electrode overlaps the first electrode;

d) separating the final assembly of steps a), b) and c) into a plurality of said electroactive devices.

As can be seen, this method allows for the simultaneous formation of a plurality of devices using common steps a), b) and c), thereby reducing manufacturing costs.

Preferably, steps b) and c) are repeated to form a plurality of mutually stacked electrode pairs to produce a device that can be controlled at a low voltage.

The invention will be more clearly understood with reference to the following detailed description thereof. The detailed description of the invention will be explained with reference to the accompanying drawings.
1 is a cross-sectional view of a lens to which no voltage is applied.
Figure 2 is a plan view of the lens of Figure 1;
3 is a view showing a state where a voltage is applied to the lens of FIG.
4 is a diagram showing the first step of the manufacturing process.
5 is a diagram showing the second step of the manufacturing process.
6 is a diagram showing a third step of the manufacturing process.
7 is a diagram showing a fourth step of the manufacturing process.
8 is a view showing the fifth step of the manufacturing process.
9 is a cross-sectional view showing a state where no voltage is applied to an assembly of two lenses, a case where a voltage is applied a little, and a state where a voltage is applied a lot.
10 is a view showing an assembly in which four lenses are stacked.
11 is a view showing a lens including a graded electrode.
12 is a plan view of the beam deflector.
13 is a cross-sectional view of a beam deflector having three different states, taken along line XIII in Fig.
14 is a diagram showing another embodiment of an optical device having a buffer layer.
15 is a diagram showing another embodiment of an optical device having a lead layer.
16 is a view showing another embodiment of an optical device having a lead layer and a buffer layer.

Justice

The term "axial direction " is used to refer to a direction generally perpendicular to the surface of the central region of the optical element in a relaxed state. If a substrate is present, the substrate will in most cases be generally vertically aligned with respect to the axial direction.

The term "radial" is used to refer to a direction perpendicular to the axial direction.

Introduction

The invention may be embodied in various forms, for example as an electro-active lens, a beam deflector or an anti-jittering device. Some of these applications are described below.

Electro-active lens

Electro-active lenses as one possible embodiment of the present invention are shown in Figs. 1 and 2. Fig. The lens includes the elastic optical element 1 and the electro-active element 2. In this embodiment, the optical element 1 is circular and the electro-active element 2 surrounds the optical element. However, as noted below, the present invention is applicable to non-circular lenses such as, for example, cylindrical lenses, as long as the electro-active elements 2 are disposed laterally adjacent one or more sides of the optical element 1 Can also be implemented.

The electroactive device 2 comprises at least two vertically stacked electrodes 3a-3e, preferably at least two, which form at least one pair of electrodes stacked on each other, preferably several electrode pairs.

The first electrode 3a on the uppermost layer is electrically connected to the first section 4a of the side wall by the lead 9a and the second electrode 3b next is electrically connected to the second section of the side wall by the lead 9b, The third electrode 3c is connected to the first section 4a again by the lead 9c and the fourth electrode 3d is connected to the second section 4b by the lead 9d, And adjacent electrodes are connected to different sections of the side wall. The side walls have electrical conductivity and are formed of a solid material such as a conductive polymer. When a potential difference is applied to the two sections 4a and 4b of the side wall, the same potential difference is applied across each pair of adjacent electrodes of the electrodes 3a to 3e.

The electroactive material 5 is located in the gap between the electrodes 3a-3e. That is, all the gaps between the electrodes are filled with the electroactive material 5. The electroactive material is a material that yields the Maxwell stress caused by the coulomb force between the electrodes when a voltage is applied between adjacent electrodes. Preferably, the electroactive material 5 is a solid such as a dielectric elastomer or gel.

The optical element 1 of the lens can be formed of the same material as the electroactive material 5, which simplifies the manufacturing process as described below. However, the optical element 1 may be formed of a material that allows the physical properties of the optical element 1 and the electroactive material 2 to be independently optimized, which is different from the electroactive material 5.

The optical element 1 is a transparent elastic solid or gel, and is put into a mechanical relaxed state for the reason described above when no voltage is applied to the electrodes 3a-3e. The optical element is preferably made of a single material.

The functions of the lenses of Figs. 1 and 2 will be described with reference to Fig. As can be seen in the figure, when a non-zero voltage (V) is applied across all pairs of adjacent electrodes formed by the electrodes 3a-3e, the coulomb force between the electrodes and / Due to the rearrangement, the axial distance between the electrodes decreases or increases, depending on the electroactive material used. In particular, liquid crystal elastomers can be made to expand in the direction of an applied electric field, while most other materials will shrink.

When the electroactive material is shrunk due to application of an electric field, the thickness of the electroactive device 2 is reduced. Since the electroactive element 2 is laterally coupled to the optical element 1, a compressed first region is created in the optical element adjacent to the electrodes. This again causes the material of the optical element 1 to be displaced in the radial direction toward the center of the optical element 1, usually in the direction away from the compressed first region. This forms a second region that expands axially in the optical element due to the incompressibility of the material. In Fig. 3, the axial expansion region appears at the center of the optical element 2.

When the electro-active material expands along the applied electric field, the thickness of the electro-active element 2 increases and the first region of the optical element 1 expands in the axial direction while the second region shrinks.

Therefore, when a voltage is applied to the electrodes, redistribution of the material occurs in the optical element 1, which again affects the surface curvature of the optical element. Owing to the limitations given by the shrinking electroactive device, the optical element 1 becomes thinner in the regions adjacent to the electrodes to which the voltage is applied, and becomes thicker in the other regions.

Depending on the thickness and the volume of the optical element 1 and the electroactive element 2, if the distance between the electrodes decreases, the fact that the electroactive material 5 between the electrodes is compressed when a voltage is applied, Thereby contributing to the deformation of the element 1. [ This compression is converted into a lateral expansion of the material (constant volume approximation), which leads to the flow of material from the electroactive device 2 to the optical device 1, thereby making the optical device 1 thicker, . Particularly when the walls 4a and 4b are solid, preferably in the case of a rigid ring, the lateral expansion is directed inward and applies pressure to the elastic material of the optical element 1, so that the surface of the optical element is deformed. As shown in Fig. 3, if the relaxed surface (Fig. 1) is intrinsically flat, the convex lens surface is formed by convexing the surface outward due to such deformation, It affects the focal length.

As mentioned, the lens according to the present invention does not necessarily have to be a circular lens. As mentioned, the lens may be cylindrical, for example. In this case, the optical element 1 is formed of a transparent elastic material of elongated strip, and at least one elongated electroactive element 2 is arranged along at least one side of the optical element, The electroactive element 2 can be compressed or expanded in proximity to the electrodes in the optical element 1 to create a first region. Also in this case, it is preferable that a solid wall is disposed on the second (opposite) side surface of the electroactive device 2, and the electroactive material 5 is prevented from yielding in this direction, So that the material substance displacement is directed to the optical element 1.

As can be seen in Figures 1 to 3, the lens preferably comprises a transparent solid substrate 7 on which the electro-active elements 2 and the optical elements 1 are arranged. The substrate provides mechanical stability to the device and simplifies the manufacturing process as described below. However, if the optical element 1 has sufficient mechanical stability, the substrate 7 may be omitted.

In order to obtain strong Coulomb force even when the applied voltage is small, the interval between the adjacent electrodes 3a to 3e should not be too far apart. Preferably, the distance between two adjacent electrodes is preferably less than 250 [mu] m, particularly about 10 [mu] m, and should be sufficiently short to allow significant deformation at a voltage of 1 kV or less.

The electrodes must be compliant. That is, the electrodes must be able to be maintained without damage to the deformation of the electro-active element 2. Thus, preferably the electrodes are made of one of the following materials.

- Carbon nanotubes (see "Self-clearable carbon nanotube electrodes for improved dielectric elastomer actuators ", Proc. SPIE, Vol. 6927, 69270P (2008)).

- carbon black (see "Low voltage, highly tunable diffraction grating based on dielectric elastomer actuators ", Proc. SPIE, Vol. 6524, 65241N (2007)).

- Carbon grease

- ions (Au, Cu, Cr, ....) (see "Mechanical properties of electroactive polymer microactuators with ion-implanted electrodes", Proc. SPIE, Vol. 6524, 652410 (2007)

- Fluid metal (for example, Galinstan)

- metal powders, especially metal nanoparticles (gold, silver, copper)

- conductive polymer

- rigid electrodes connected to deformable leads

The material for the optical element 1 and the electroactive material 5 for the electroactive element 2 may include, for example, the following materials or may be composed of the following materials.

- gel (Optical Gel OG-1001 supplied by Litway),

- elastomers (such as TPE, LCE, PDMS Silicone Guard 186, acrylic, urethane)

- Thermoplastic material (ABS, PA, PC, PMMA, PET, PE, PP, PS, PVC, ...)

- Duroplast

The geometries of the electrodes 3a to 3e need not be the same. Fig. 11 shows a preferred embodiment in which the inner diameter of the electrodes 3a-3e becomes gradually larger toward the surface of the device. In other words, at least the electrode 3a closest to the top surface has a larger inner diameter than the electrode below it. (In this specification, "upper surface" refers to the surface of the lens that is deformed upon application of voltage.)

This design reduces the mechanical strain in the electro-active material 5 and in the optical element 1 material upon voltage application.

In general, the inner diameter of at least one of the electrodes 3a-3e may be different from the inner diameter of at least some of the other electrodes. This allows a finer control over the deformation of the optical element 1.

In the following, a preferred manufacturing process will be described with reference to Figs. In this process, a plurality of electro-active lenses are simultaneously fabricated on a common wafer. The common wafer may be preformed to include a fixed structure, such as a rigid lens, for example, in combination with the optical element 2.

The process starts from the substrate 7, which is inherently larger than the individual lens (step a, Fig. 4). An electrode (3e) positioned at the bottom of the plurality of adjacent lenses is deposited on the substrate. Any suitable method, such as sputtering with subsequent masking and etching steps, may be used to fabricate these electrodes as long as they provide compatibility of the electrode material with the substrate.

Next, the layer 5a of the electroactive material 5 is applied onto the substrate 7 (step b, Fig. 5). The layer 5a may have a thickness of, for example, 10 mu m.

In the next step (step c, Fig. 6), a plurality of second electrodes, i. E. Electrode 3d, is applied over layer 5a of electroactive material. The electrode 3d is registered with the electrode 3e and one electrode 3d overlaps each electrode 3e.

Next, step b is repeated. That is, the additional layer 5b of the electro-active material is applied as shown in Fig. 6, and until a sufficient height stacked structure having a plurality of electrode pairs stacked up and down as shown in Fig. 7 is manufactured, c is repeated.

After completing the layer structure of Fig. 7, the walls 4a, 4b pre-assembled and applied to a common carrier, for example (not shown), are pressed from above into the layer structure. Since the layers 5a, 5b, ... are soft materials, the walls 4a, 4b can enter the layers as shown in Figure 8, thereby removing common carriers (not shown) of the walls . The walls 4a and 4b are positioned so that they contact the electrodes 3a to 3e. To this end, leads 9a-9e are provided on the electrodes 3a-3e, as clearly shown in Figure 7, as well as Figures 1 and 2, and the leads 9a- 4a or 4b) of the lens.

Finally, the product of this step is separated into a plurality of electro-active lenses, for example by cutting between the walls of adjacent lenses along line 10, as shown in Fig. Alternatively, if the substrate 7 is sufficiently flexible, the separation of the lenses may be achieved by, for example, pressing the walls 4a, 4b through the substrate 7, as well as through the layers 5a, 5b, ≪ / RTI > Alternatively, the product shown in Fig. 7 may be first cut, whereby the walls 4a, 4b or other means for providing contact to the electrodes 3a-3e are applied individually to each lens.

In step b, for example, the following method may be used to apply the layers 5a, 5b, ... of electroactive material.

- spin coating which is subsequently cured

- a spray which is subsequently cured

- Printing (for example, screen printing)

- chemical vapor deposition, especially PECVD (plasma chemical vapor deposition)

- a method of pre-assembling the material layers to apply them onto the substrate, preferably onto the substrate, in which case the layer may optionally be inelastically stretched prior to application to reduce the thickness of the layer.

For example, the following materials can be used for electro-active materials as well as for optical elements.

Gel [Optical Gel OG-1001 supplied by Litway Co.]

- Polymers (e.g., Neukasil RTV 25, PDMS Sylgard 186 supplied by Dow Corning)

Acrylic materials (such as VHB 4910 supplied by 3M Company)

- elastomer

In step c, for example, the following method can be used to apply the compliant electrodes 3a-3d, optionally the electrode 3e.

&Quot; Mechanical properties of electroactive polymer micro actuators with ion-implanted electrodes ", Proc. SPIE, Vol. 6524,652410 (2007)

- PVD, CVD

- Evaporation

- Sputtering

- Printing, in particular contact printing, inkjet printing, laser printing and screen printing

- Field Guided Self-Assembly [L. Seemann, A. Stemmer and N. Naujoks, Nano Letter, Quot; Nano Letters 7, 10, 3007-3012, 2007 "

- Brushing

- Electroplating

Alternatively, the optical element 1 may be configured to have a predetermined shape in a relaxed state and / or a deformed state of the optical element. Examples of such lenses are described below with reference to Figs. 9 and 10. Fig. A suitable lens shape (in the relaxed state) may be, for example, as follows.

- spherical lenses (convex and concave)

- Aspheric lenses (convex and concave)

- flat (flat)

- Square, triangular, linear or pyramidal

(E. G., An antireflective coating) is incorporated into the open aperture of the optical element < RTI ID = 0.0 > 1 < / RTI > with a compliant electrode comprising a polymer layer, .

Any of the following methods may be used to shape the lens.

a) Castings, especially injection molding

b) For example, nano-imprinting by hot embossing of nanometer size structure,

c) etching (e. g., chemical or plasma)

d) Sputtering

e)

f) soft lithography (i.e. molding of the polymer on a preformed substrate)

g) chemical self-assemblies [e.g., "Surface tension-powered self-assembly of microstructures - the state-of-the-art ", R.R.A. Syms, E. M. Yeatman, V.M. Bright, G.M. Whitesides, Journal of Microelectromechanical Systems 12 (4), 2003, pp. 387-417)

h) electromagnetic field guide pattern formation methods (e.g., "Electro-magnetic field guided pattern forming ", L. Seemann, A. Stemmer, and N. Naujoks, Nano Lett., 7 (10), 3007-3012, 2007. 10.1021 / nI0713373)

As will be appreciated by those skilled in the art, some of these methods are directly compatible with the fabrication process described with reference to Figures 4-8, for example, methods c) and d) Can be achieved in the depicted product. Some other methods will require additional steps. For example, an array of convex lenses on a common carrier may be produced by the method a), b) or e) to k) and then applied to the top of the product of Fig.

A variety of electro-active lenses of the type described above can be combined to form a multi-lens assembly.

An example of such an assembly in which two electro-active lenses 11a and 11b are mounted on opposite sides of a solid, transparent common substrate 7 is shown in Fig. As clearly shown in the left side of the drawing, in a state in which no voltage is applied, the lens 11a has a flat surface, while the lens 11b has a concave surface. Since the lens 11a can be manufactured, for example, as shown in Figs. 4 to 8, the optical element of the lens 11b can be constituted subsequently by using, for example, the method c) or d) do.

When a small voltage is applied, as shown in the center part of the drawing, the lens 11a is in a convex state although it has a small curvature, while the lens 11b is in a concave state. Finally, as shown in the right side of FIG. 9, when a sufficient voltage is applied, all of the lenses 11a and 11b become convex.

The lens of the present invention may be combined into a more complex structure. An example of such an assembly is shown in FIG.

The assembly of FIG. 10 includes four electroactive lenses 11a, 11b, 11c, and 11d, as well as four rigid lenses 12a, 12b, 12c, and 12d stacked up and down. The walls 4a, 4b and the additional spacer elements 13a, 13b are used to hold the lenses at mutually correct distances. In the example of Fig. 10, each electro-active lens 11a-11d is attached to one side of the substrate 7, and the rigid lenses 12a-12d are arranged on opposite sides of the substrate.

In the embodiment of Fig. 10, each rigid lens is attached to the substrate 7. However, one or more rigid lenses may be individually mounted to the substrate.

In the absence of an electromagnetic field, the shapes of the electro-active lenses 11a, 11b, 11c, and 11d can be formed using the above-described configuration method.

Spherical lens

In many applications, the lens should be spherical. The overall thickness of the electroactive device 2 and the optical element 1 must be considerably large in order to form a lens that is generally spherical with the design shown in Figures 1 to 10. [ Otherwise, particularly when the electroactive layer is bonded to the substrate 7, the deformation at the time of voltage application occurs severely near the electrode, but weakly at the lens center.

On the other side, when the total thickness of the optical element 1 and the electroactive layer 2 is increased, a relatively large number of individual layers 5a, 5b, ... are required when using the manufacturing process of Figs. 4 to 8, This causes the process cost to increase.

For this reason, it is preferable that the design shown in Fig. 14, that is, the design in which the electrodes 3a to 3e are separated from the substrate 7 by the elastic buffer layer 30 is preferable. The buffer layer 30 disposed between the substrate 7 on one side and the electroactive device 2 on the other side and the optical element 1 is formed so that the material of the optical element 1 can move more freely, That is, the material protects the optical element 1 from the mechanical constraint of the rigid substrate 7. Therefore, it is preferable that the buffer layer 30 is formed of a material having relatively softness. That is, the buffer layer has an elastic modulus that is smaller than or equal to the Young's modulus of the optical element 1.

The buffer layer 30 can be attached over the entire surface of both the substrate 7 and the optical element 1 so that the substrate and the optical element 1 can be optically coupled to each other without restricting the movement of the optical element 1 when a voltage is applied to the electrodes. Connect the devices.

Another method for improving the surface shape of the spherical lens, i.e., forming the spherical lens close to the ideal spherical lens, is shown in Fig. In the embodiment of Fig. 15, the lead layer 31 is attached to the uppermost layer of the optical element 1, that is, the opposite side of the substrate 7. The lead layer 31 is stiffer than the optical element 1. That is, the lead layer has a modulus of elasticity larger than that of the optical element 1. For the implementation of a high quality lens, in particular the modulus of elasticity should be about 60 times greater than the modulus of elasticity of the optical element 1. As the layer thickness becomes thinner, the modulus of elasticity must be increased to achieve good optical quality.

The methods of FIGS. 14 and 15 can be combined as shown in FIG. 16, wherein the optical device includes both a buffer layer 30 and a lead layer 31.

Suitable materials for the buffer layer 30 and the lead layer 31 are, for example, PDMS, acrylic or polyurethane. The buffer layer generally has an elastic modulus of 200 kPa or less, and the lead layer has an elastic modulus of 10 MPa or more. These materials are preferably combined with elastomers, acrylics and polyurethanes for electroactive materials and lens elements.

beam Deflector

The above-described techniques can be applied not only to lenses but also to various other electro-active optical devices such as a beam deflector or a jitter preventing device.

An example of a beam deflector or mirror is shown in Figs. 12 and 13. Fig. The components are basically the same as the devices of Figs. 1 to 3, but the electrodes 3a and 3c are separated into two electrode sections 3a 'and 3a' 'and 3c' and 3c '', respectively, The section extends over approximately 180 [deg.] Of the optical element 1. Thus, the wall is divided into three sections 4a, 4b and 4c, the section 4a to the electrode sections 3a 'and 3c', the section 4b to the electrode sections 3a 'and 3c' The section 4c is connected to the electrode sections 3b and 3d. Voltage V1 may be applied between sections 4a and 4c and voltage V2 may be applied between sections 4b and 4c.

If V1 = V2 = 0, the surface of the optical element 1 is flat and horizontally formed as shown in the left side of Fig. If V1 ≠ 0 and V2 = 0, the surface of the optical element is tilted substantially to one side, whereas if V1 = 0 and V2 ≠ 0, the surface of the optical element is substantially tilted to the opposite side.

This type of device can be used as a beam deflector in transmission or reflection.

When the device is operated upon transmission, the beam extending through the optical element 1 can be deflected left or right according to V1 and V2, as shown by arrow 21.

At least one of the surfaces of the optical element 1 may be provided with a mirror element, such as a reflective coating 25 or a rigid reflective mirror plate, when the device is operated upon reflection, Respectively, to the right or left.

The mirror element may be, for example, a mirror plate attached to surface 20, for example a coating such as a liquid metal coating (e.g., Galinstan).

Figure 12 shows a circular beam deflector. However, this shape may be, for example, rectangular, and the electrodes 3a 'and 3a "are arranged on opposite sides of the rectangle.

Other devices

The techniques described above may also be applied to other types of devices, such as optical phase retarders (e.g., using the techniques disclosed in WO 2007/090843).

The device may also be combined with another optical element such as a planar or curved mirror, a diffraction grating or a hologram.

Explanation

In the embodiments described above, ring sections 4a, 4b and 4c were used for contact with electrodes. Other contact means may of course be used. For example, a needle-like structure of metal may be inserted through the leads 9a, 9b, 9c for providing a common contact. Alternatively, conductive vias filled with conductive materials may be incorporated into the electroactive material stack during the layer by layer process. This contact method allows the electrodes 3a-3e to be contacted from one side of the electroactive material laminate.

In the examples of FIGS. 1 to 3, the first potential is commonly applied to the electrodes 3a, 3c, and 3e while the second potential is applied to the electrodes 3b and 3d. Or individual potentials may be applied to some or all of the electrodes to more precisely control the deformation of the electroactive device 2. [

In a particularly preferred embodiment, an antireflection layer may be provided on one side or both sides of the optical element 1. [ The antireflection layer may be composed of the following elements.

A "nanometer structure" formed in the material of the optical element 1 itself or in a separate coating material. Such a structure has a size that is far less than the wavelength of light, for example, a size of less than 400 nm. The structure may be applied, for example, by etching, molding, casting or stamping.

- Antireflection thin film coating layer.

In another preferred embodiment, the shape of the optical element 1 may be influenced by a locally rigid or soft portion of the optical element in its deformed state, for example by UV curing or chemical treatment. An example of this embodiment is shown in Fig. 13, wherein the hatching region is created by a local curing process and represents a rigid portion 26 below the surface 20 that improves the flatness of the surface 20 upon voltage application. The rigid portion may be formed of a material different from the rest of the optical element, and may be added to the optical element in such a way that it is embedded or mounted on the surface of the optical element, for example. The position of the rigid portion changes when a voltage is applied to the electrodes.

In general, the material of the optical element 1 may have non-uniform hardness, and in particular may comprise an inhomogeneously polymerized polymer.

Further, the optical element 1 may be an assembly of two or more materials suitably combined with each other, for example, to correct chromatic aberration using two materials having different degrees of optical dispersion.

Further, the optical element 1 may be, for example,

- Microstructures such as diffractive structures and hologram structures,

- can be further structured by a deformable coating such as a reflective or antireflective coating (such as those described above) or an absorbent coating.

Some examples

The electro-active optical device can be used in a wide variety of fields as follows.

- Camera of the type used in mobile phone, digital SLR camera, in-car camera, surveillance system (with zoom and autofocus)

- Optical projector parts for macro projectors and nano projectors in beamer and mobile phone projectors

- industrial applications including laser cutting or welding

- microscope, magnifying glass

- Vision correction (lens implanted in human eye)

- Endoscope

- Magnifying glass

- Vision system like a camera

- Research applications for quantum computation

- Communication applications (amplitude modulation)

- laser applications such as those used for deflected laser beams

- telescope

- display

The present invention is not limited to the embodiments of the invention shown and described herein, but may be embodied and practiced in various forms within the scope of the following claims.

Claims (29)

An electro-active optical device comprising:
A solid substrate 7,
An elastic optical element 1 arranged on the solid substrate 7,
An electroactive device (1) including a plurality of electrode pairs arranged laterally adjacent to the elastic optical element (1) and each comprising two electrodes (3a-3e) and having an elastic electroactive material (2)
Wherein an axial interval between the electrodes is changed when a voltage is applied across at least one pair of electrodes to change the volume of the first region of the elastic optical element (1) adjacent to the at least one pair of electrodes, Radially displaces the material in the elastic optical element (1) between the first region and the second region of the elastic optical element (1), one of the regions being elastically expanded and the other of the regions being elastically The elastic optical element 1 is elastically relaxed in a state in which no voltage is applied to the plurality of electrode pairs,
Wherein the plurality of electrode pairs are stacked vertically with a plurality of gaps between the electrode pairs, the gaps being filled by the elastic electroactive material (5)
The electroactive optical device further comprises a buffer layer (30) arranged between the solid substrate (7) on one side and the electroactive device (2) and the elastic optical element (1) Has an elastic modulus smaller than or equal to the elastic modulus of the elastic optical element (1)
The electroactive optical device further comprises a lead layer (31) attached to the elastic optical element (1), wherein the lead layer (31) is made of an electrically active material having an elastic modulus greater than that of the elastic optical element Optical device. The electro-optical device according to claim 1, wherein the elastic optical element (1) is solid or gel. The electroactive optical device as claimed in claim 1 or 2, wherein the electroactive device (2) comprises or consists of a material selected from the group consisting of a gel, a polymer, an acrylic material and an elastomer. The electro-optical device according to claim 1 or 2, wherein the elastic optical element (1) is the same material as the elastic electro-active material (5). The electro-optical device according to claim 1 or 2, wherein the elastic optical element (1) is a material different from the elastic electro-active material (5). The electro-active optical device according to claim 1 or 2, wherein the electro-active element (2) surrounds the elastic optical element (1). 3. An electro-optical device according to claim 1 or 2, characterized in that the elastic optical element (1) is arranged on a first side of the electro-active element (2) Further comprising solid walls (4a, 4b) in said first side, said second side facing said first side. 8. The electro-optical device according to claim 7, wherein each said electrode (3a-3e) is electrically connected to one of at least two different sections (4a, 4b) of said solid wall. The electroactive device according to claim 1 or 2, wherein the electroactive device (2) comprises a group comprising a carbon nanotube, carbon black, carbon grease, a metal ion, a fluid metal, a metallic powder, a conductive polymer, And at least one electrode made of at least one material selected from the group consisting of: The electro-active optical device according to claim 1 or 2, wherein the buffer layer (30) is attached to the solid substrate (7). 3. The electro-optical device according to claim 1 or 2, wherein the lead layer (31) is attached to a side surface of the elastic optical element (1) facing the solid substrate (7). 3. The electro-optical device according to claim 1 or 2, wherein the inner diameter of at least one of the electrodes (3a-3e) is different from the inner diameter of at least a part of the other electrodes. 13. The electro-optical device according to claim 12, wherein the electrode (3a) closest to the top surface of the electro-active optical device has an inner diameter larger than that of the electrode (3b) . 3. The electro-optical device according to claim 1 or 2, further comprising a mirror element (25) on at least one surface of the elastic optical element (1). 3. The electro-optical device according to claim 1 or 2, further comprising a rigid element (26) in the elastic optical element (1). 3. The electro-optical device according to claim 1 or 2, further comprising an antireflection layer on at least one surface of the elastic optical element (1). 3. The electro-optical device according to claim 1 or 2, wherein the elastic optical element (1) has an inhomogeneous hardness. 18. The electro-active optical device according to claim 17, wherein the elastic optical element (1) comprises an inhomogeneously polymerized polymer. The electro-active optical device according to claim 1 or 2, wherein the electro-active optical device is an electro-active lens. An assembly of an electroactive optical device according to any one of the preceding claims,
Wherein at least two electroactive optical devices (11a, 11b) are laminated together. 21. The assembly of claim 20, wherein the electroactive optical devices (11a, 11b) are mounted on opposite sides of a common solid substrate (7). A method of manufacturing an electro-optic device according to any one of claims 1 to 3,
a) providing a plurality of first electrodes 3e;
b) applying a layer (5a) of an elastic electroactive material (5) over said first electrode (3e)
c) applying a plurality of second electrodes (3d) on the layer (5a) of the elastically electroactive material (5), wherein each second electrode (3d) overlaps the first electrode Applying a second electrode (3d)
d) repeating steps b) and c) to form a plurality of mutually stacked electrode pairs,
e) separating the final product according to step a), b), c) and d) into a plurality of said electroactive optical devices. Method according to claim 22, characterized in that, between step d) and step e), the layer (5a, 5b, ...) of the elastic electroactive material (5) 4a, 4b are inserted. 23. The method according to claim 22, wherein the elastic optical element (1) is made of a single material. delete delete delete delete delete

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